1. Field of the Invention
This invention relates generally to gaseous-material evacuation systems and more particularly to such systems having filters for cleaning evacuated gases.
2. Description of Related Art
This invention has uses in the area of waste disposal, such as in devices and systems for evacuating aerosol cans, and other containers of pressurized gases and residue contents.
Pressurized aerosol cans, and other pressurized containers, have widespread usage in homes and industry. It has long been recognized that improper disposal of such containers constitutes a safety hazard in that excessive external heat and/or pressure can cause them to explode if they have not been relieved of internal pressure. Similarly, the release of contents, both propellant gases and dangerous residue materials, from such containers often damages the environment.
Due to these hazards, the Environmental Protection Agency (EPA), an agency of the U.S. Government, regulates disposal of pressurized containers as well as their contents for industries. These regulations mandate regulated businesses and industries dispose of pressurized containers as hazardous waste. The Resource Conservation and Recovery Act mandates that the pressure within aerosol cans equal atmosphere prior to disposal. Further, these regulations require that certain contents of pressurized containers be captured and disposed of in particular manners. Depending upon the natures of such contents, disposal methods can involve permanent disposal through incineration, landfills or other means; treatment and permanent disposal; treatment and recycling; and treatment and reclamation for a new use. An example of reclamation would be recovering a solvent contained in waste paint for use as a fuel. But, whichever disposal method is used, the EPA requires many industries to relieve the pressure in pressurized containers prior to transporting them for disposal.
In addition to the above requirements of the EPA, many states within the United States and countries outside the United States have requirements similar to, or even stricter than, those of the EPA. For example, California closely regulates release of gases into the atmosphere. In this respect, California considers some propellants used in aerosol cans to be contaminants, particularly when they contain small aerosolized particles of materials, such as insecticides, paints and the like, which were in the aerosol cans.
Further, while EPA regulations do not apply to individuals and many small businesses, many of these still desire to dispose of hazardous contents of such containers, and the containers themselves, in a manner which provides personal safety and protects the environment, and would do so if a reliable, inexpensive apparatus therefor exists.
There have been a number of prior-art devices suggested for piercing pressurized containers such as are described in U.S. Pat. No. 3,303,968 to Compere; U.S. Pat. No. 3,333,735 to Odasso; U.S. Pat. No. 3,828,976 to Sidelinker; U.S. Pat. No. 3,926,340 to Tygenhof; U.S. Pat. No. 4,500,015 to Penney, and U.S. Pat. No. 4,934,055 to Chambers. Some of these devices do not adequately provide for disposal of gases and residual contents of the pressurized containers, such as the devices of Compere, Sidelinker, Odasso, Tygenhof and Penney.
The device of Chambers (U.S. Pat. No. 4,934,055) does provide for disposal of contents of pressurized cans, however, this device appears to be somewhat limited in application having an unduly small, custom-built, reservoir and apparently requiring an undue amount of strength and dexterity to operate. Also, the device of this patent does not appear to be sufficiently durable to withstand repeated use.
A number of US Patents to Michael Campbell describe systems for evacuating gaseous materials from aerosol containers and other types of containers, see U.S. Pat. Nos. 5,163,585; 5,265,762; and 5,992,475. Most of these systems involve sealing a wall of an aerosol can on a seat, puncturing the can below the seat, and evacuating the contents of the can into a drum.
A widely used device for piercing pressurized containers is described in U.S. Pat. No. 5,265,762 to Campbell et al. This Campbell et al. patent describes a puncturing device for aerosol containers which includes an elongated tubular housing having male threads at a second end for being screwed into a first, or large, bung-plug hole (bunghole) of an off-the-shelf drum, such as a 15, 30 or 55 gallon drum. An aerosol can to be disposed of is inserted into a first opening at a first end of the cylindrical housing, nozzle-end-first, until a shoulder of the aerosol can engages a sealing shoulder seat in the elongated tubular housing. A puncturing member, as part of a mechanism mounted to the side of the housing, is driven through the housing to create a puncture opening in the aerosol can below the sealing shoulder seat. Propelling gas and residue material are driven from the aerosol can, by pressure of the propellant gas, through the puncture opening and through the second end opening of the housing into the drum. The sealing shoulder seat prevents the propellant gas and residue from retro-movement toward the first end opening of the housing (which opens to the environment) and ensures that these materials go into the drum.
Campbell et al (U.S. Pat. No. 5,265,762) also describes a filter screwed into a second, small, bunghole of the drum for filtering propellant gases escaping from the second bunghole of the drum to the environment for cleaning escaping gaseous vapors of atmosphere-harmful materials.
U.S. Pat. No. 5,992,475 to Campbell discloses a spring-activated check valve at the second end of the tubular wall of the housing with a spring-activated valve poppet positioned at the second end for opening and closing in response to pressure. Basically this check valve opens to allow propellant gases to escape from the punctured aerosol cans into the drum and then closes to prevent retrograde movement of the gases from the drum back through the piercing-device housing once the cans are removed. U.S. Pat. No. 5,181,462 to Isaac also describes a similar valve.
Other patents which describe devices and systems relating to the system described in Campbell et al (U.S. Pat. No. 5,265,762) include U.S. Pat. No. 3,358,883 to Loe; U.S. Pat. No. 3,828,976 to Sidelinker; U.S. Pat. No. 3,926,340 to Tygenhof; U.S. Pat. No. 4,349,054 to Chipman et al; U.S. Pat. No. 5,114,043 to Collins, Jr.; U.S. Pat. No. 5,181,462 to Isaac; U.S. Pat. No. 5,271,437 to O'Brien et al; U.S. Pat. No. 5,284,997 to Spearman et al; U.S. Pat. No. 5,309,956 to Hajma; U.S. Pat. No. 5,365,982 to O'Neill; U.S. Pat. No. 6,422,273 to Campbell; and U.S. Pat. No. 6,644,515 to Campbell. Additional patent documents disclosing devices for puncturing pressurized cans and/or disposing of their contents include U.S. Pat. No. 5,067,529 to Gonzalez-Miller et al., U.S. Pat. No. 4,459,906 to Cound et al., and U.S. Pat. No. 4,407,341 to Feldt et al. as well as Soviet patent document 821399 and German Offenlegungsschrift 1,607,991. All of these patent documents disclose relatively complicated, expensive, and large machines.
Although these prior-art devices prevent retrograde movement of unfiltered gases through the piercing-device housing back to atmosphere, they do not filter gases as they pass through the filter from the small bunghole in a manner which indicates when the filter is saturated and which inhibits flashback. Flow of such gaseous materials through the filter to atmosphere can be dangerous because personnel standing near the drum containing evacuated residue and gases are not aware that dangerous gases are being continually released. For example, one might smoke a cigarette close to a storage drum, thereby possibly igniting gases escaping from the drum through the filter. For this reason, it is desirable that evacuation systems filter residue and/or contaminants from the gaseous materials that escape into the atmosphere and prevent flashback so that the fumes are not ignited.
It is an object of the invention to provide a filter assembly for use in conjunction with a storage drum into which the contents of pressurized cans have been emptied. In common use, the filter assembly is used in conjunction with a device for puncturing a pressurized container to relieve the pressure therein and for releasing gases and residual contents thereof into a storage drum.
It is further an object to provide a filter assembly which is not unduly complicated, which can be easily transported to a site and installed thereat, which is relatively easy and convenient to use requiring no outside power, which can be used with off-the-shelf receptacles in common use, which is relatively inexpensive to manufacture, which operates in a manner complying with EPA regulations in a safe and efficient manner, and which can accommodate pressurized containers of various sizes. Thus, it is an object of this invention to provide a device for allowing desired easy flow of evacuated gaseous materials through a filter of an evacuation system when the evacuation system is being actively use for evacuation, but for stopping such flow when gaseous materials are not being actively evacuated.
Finally, it is an object of the present invention to accomplish the foregoing objectives in a simple and cost effective manner.
The above and further objects, details and advantages of the invention will become apparent from the following detailed description, when read in conjunction with the accompanying drawings.